Illinois became the first state in the nation to ban companies which boycott Israel or its illegal settler colonies from doing business with the state.

Jewish Telegraphic Agency reports the Illinois Investment Policy board named 11 companies barred from doing business with America’s fifth-most populous state under a 2015 bill passed by the state legislature and signed into law by Republican Gov. Bruce Rauner.

“Today’s actions were truly historic and will lead the way for the dozens of other states following Illinois’ lead,” a senior Rauner administration official told JTA on Friday.

Some 20 states have passed laws or are considering measures to punish companies supporting BDS. The majority of these sanction only businesses boycotting Israel but nine states, including Illinois, extend penalties to firms boycotting Israeli companies operating in the occupied West Bank. Under international law, both the occupation and the settlements are illegal, although Israel disputes this.

The sanctioned companies include ASN Bank of the Netherlands, which disinvested from a light rail project in Jerusalem, South African importer Karsten Farms, Danske Bank, the largest bank in Denmark and Sweden-based Nordea Bank. Some of the blacklisted companies, including British security firm GS4 and Dexia Bank of Belgium, said they divested from their Israeli holdings for commercial reasons, not out of support for the BDS movement.

BDS, a global campaign for Palestinian human rights, is a peaceful protest movement supported by academics, political organizations, religious leaders, celebrities and others, including prominent Israeli and non-Israeli Jews. Former president Jimmy Carter, who won the Nobel Peace Prize for brokering a lasting peace between former bitter enemies Israel and Egypt, is the most prominent American BDS supporter. Carter has accused Israel of perpetuating “even worse… apartheid than we witnessed in South Africa.” South African anti-apartheid icon Desmond Tutu, another Nobel Peace Prize winner, has also urged an international boycott of Israel over its “apartheid” treatment of the Palestinians. Former UN human rights official Richard Falk, an American Jew, is a BDS supporter who has repeatedlyasserted that Israeli settlement expansion is a “form of ethnic cleansing.”

While some prominent Jewish critics of BDS, including the Anti-Defamation League, the Simon Wiesenthal Center and Israeli government officials, have accused the movement of being antisemitic because it singles out Israel for condemnation in a world full of human rights violators, BDS supporters call allegations of antisemitism absurd, pointing to the fact that several of the movement’s leaders are Jewish. BDS backers also accuse Zionists of labeling Israel critics as antisemitic or, if the critics are Jewish, “self-hating Jews,” in a bid to deflect legitimate criticism of Israeli policies and actions. The late Israeli cabinet minister Shulamit Aloni called such accusations “a trick we always use.”

In a speech to the powerful pro-Israel lobby group American Israel Public Affairs Committee’s (AIPAC) in Washington, DC on Monday, Democratic presidential frontrunner Hillary Clinton condemned BDS, linking the movement to antisemitism and “bullying” on college campuses and elsewhere. Clinton’s remarks accompany a wave of anti-BDS legislation sweeping the US, from bipartisan amendments to congressional trade bills to the “Boycott Our Enemies, Not Israel Act” introduced in the House of Representatives by Rep. Doug Lamborn (R-CO) and seven co-sponsors. Under existing US law, companies have been fined for actions deemed supportive of BDS.

Censorship of pro-BDS speech has been particularly acute on US college campuses, where pro-Palestine professors have been reprimanded or fired, anti-occupation student activists have been suspended and threatened with expulsion and pro-Palestinian groups have been de-funded. A student at George Washington University has even been disciplined for flying the Palestinian flag. The University of California system, the nation’s largest, has been debating whether to outlaw BDS as “antisemitic,” and dozens of states have passed or are considering legislation that would suspend funding of educational institutions supporting groups that boycott Israel.

In 2014, Israeli Prime Minister Benjamin Netanyahu launched a $25 million task force to fight groups that boycott Israel. This effort is complemented by tens of millions of dollars donated by Republican billionaire Sheldon Adelson and Democratic billionaire Haim Saban to fight BDS at American colleges.

“Israel is increasingly unable to defend its regime of apartheid and settler colonialism over the Palestinian people and its regular massacres of Palestinians in Gaza so is resorting to asking supportive governments in the US and Europe to undermine free speech as a way of shielding it from criticism and measures aimed at holding it to account,” Rafeef Ziadah, a Palestinian a member of the Palestinian BDS National Committee, told The Intercept, which called the punishment and even criminalization of anti-occupation, anti-settlement and pro-Palestinian activism “the greatest threat to free speech” in the Western world.